RE: [PATCH -next v4] drm/amdgpu: return 'ret' immediately if failed in amdgpu_pmu_init

[Kim, Jonathan]

Immediate return should be ok since perf registration isn't dependent on gpu hw.

Reviewed-by: Jonathan Kim <Jonathan.Kim@xxxxxxx>

-----Original Message-----
From: Mao Wenan <maowenan@xxxxxxxxxx> 
Sent: Monday, June 24, 2019 7:23 AM
To: airlied@xxxxxxxx; daniel@xxxxxxxx; Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Koenig, Christian <Christian.Koenig@xxxxxxx>; Zhou, David(ChunMing) <David1.Zhou@xxxxxxx>; dan.carpenter@xxxxxxxxxx; julia.lawall@xxxxxxx
Cc: kernel-janitors@xxxxxxxxxxxxxxx; amd-gfx@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Kim, Jonathan <Jonathan.Kim@xxxxxxx>; Mao Wenan <maowenan@xxxxxxxxxx>
Subject: [PATCH -next v4] drm/amdgpu: return 'ret' immediately if failed in amdgpu_pmu_init

[CAUTION: External Email]

There is one warning:
drivers/gpu/drm/amd/amdgpu/amdgpu_pmu.c: In function âamdgpu_pmu_initâ:
drivers/gpu/drm/amd/amdgpu/amdgpu_pmu.c:249:6: warning: variable âretâ set but not used [-Wunused-but-set-variable]
  int ret = 0;
      ^
amdgpu_pmu_init() is called by amdgpu_device_init() in drivers/gpu/drm/amd/amdgpu/amdgpu_device.c,
which will use the return value. So it should return 'ret' immediately if init_pmu_by_type() failed.
amdgpu_device_init()
        r = amdgpu_pmu_init(adev);

Fixes: 9c7c85f7ea1f ("drm/amdgpu: add pmu counters")

Signed-off-by: Mao Wenan <maowenan@xxxxxxxxxx>
---
 v1->v2: change the subject for this patch; change the indenting when it calls init_pmu_by_type; use the value 'ret' in  amdgpu_pmu_init().
 v2->v3: change the subject for this patch; return 'ret' immediately if failed to call init_pmu_by_type().
 v3->v4: delete the indenting for init_pmu_by_type() arguments. The original indenting is correct.

 drivers/gpu/drm/amd/amdgpu/amdgpu_pmu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pmu.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pmu.c
index 0e6dba9f60f0..c98cf77a37f3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pmu.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pmu.c
@@ -254,6 +254,8 @@ int amdgpu_pmu_init(struct amdgpu_device *adev)
                ret = init_pmu_by_type(adev, df_v3_6_attr_groups,
                                       "DF", "amdgpu_df", PERF_TYPE_AMDGPU_DF,
                                       DF_V3_6_MAX_COUNTERS);
+               if (ret)
+                       return ret;

                /* other pmu types go here*/
                break;
--
2.20.1